The present invention relates to beverage mixing and dispensing systems. More particularly, the present invention relates to beverage mixing and dispensing systems for effectively forming and dispensing carbonated water to be mixed in the beverages.
Carbonated beverages or soft drinks are typically formed from a combination of syrup and carbonated water or soda. The carbonated water or soda is generated by entraining carbon dioxide (CO2) gas into water under pressure in a carbonator. If an insufficient quantity of CO2 gas is entrained in the water, the soda or resulting soft drink may have a xe2x80x9cflatxe2x80x9d taste, which is unacceptable to the consumer. Consistently providing a desired level of carbonation in soft drinks has been a problem in typical soft drink fountains.
It is known that the pressure of the CO2 gas and the temperature of the water are parameters that affect the carbonation level of the carbonated water. As a rule of thumb, the colder the water, the greater the amount of CO2 that can be entrained and maintained therein. However, the temperature of the supplied water to dispensing apparatuses varies from region to region and season to season. That is, in the United States, the temperature of public water in northern states is typically lower than that of public water supplied in southern states. Likewise, the temperature of water supplied in the winter is typically lower than that of water supplied in the summer in most regions. Thus, if the temperature of the water is unregulated, the carbonation levels will vary, possibly out of an acceptable range.
To avoid problems of varying temperature of supplied water, it has been known to chill the water supplied to the carbonator and, in some cases, to chill the carbonated water flowing from the carbonator. For example, U.S. Pat. No. 5,080,261 is directed to a soft drink dispenser that pre-chills water supplied to the carbonator and cools the carbonator itself. The dispenser includes an insulated ice bin for storing ice to be used in cups into which the soft drink is to be dispensed. The bottom plate of the ice bin is in thermal contact with a cooling plate made of high thermally conductive metal. An insulated, cylindrical carbonation and cooling tank includes a bottom plate that rests intimately upon the cooling plate. In addition, a baffle plate formed of thermally conductive material extends from the bottom plate into the carbonation tank to act as a cooling fin. The ice received within the ice bin acts as a heat sink for the cooling plate and the carbonation tank. The cooling plate includes a plurality of serpentine passages that are interconnected with a water supply conduit.
In use, supplied water is pre-chilled through the cooling plate and flows into the carbonation tank where pressurized CO2 gas is supplied. The carbonated water in the carbonation tank is cooled due to the contact of the tank with the cooling plate and due to the cooling fin. When a dispensing valve is actuated to dispense a soft drink, carbonated water from the carbonation tank at a cold temperature can be mixed with a soft drink syrup and dispensed.
However, forming the carbonation tank in thermal contact with the cooling plate complicates the design of this dispensing apparatus, especially when forming the baffle plate of thermally conductive material to act as the cooling fin. Moreover, the ratio of the volume of water to the surface of the cold inner wall of the carbonator tank does not result in efficient cooling when compared with a cooling plate with serpentine passages.
U.S. Pat. No. 5,319,947 describes a beverage dispenser that includes a pre-chilled water cooling coil in a first cold plate for supplying chilled water to a carbonator, and a soda cooling coil in a second cold plate for cooling the carbonated water flowing from the carbonator. In addition, the second cold plate, which forms the bottom wall of an ice bin, is cast with an integral, semi-cylindrical sleeve extending therebelow to form a carbonator housing. The cylindrical carbonator is in intimate heat exchange contact with the sleeve in order to cool the carbonator by conduction.
However, such a casting with integral cold plate and carbonator sleeve is both difficult and expensive to manufacture.
It is, therefore, an aspect of the present invention to provide an apparatus for efficiently mixing and dispensing carbonated beverages.
It is another aspect of the present invention to provide an apparatus for efficiently forming carbonated beverages that is simple to manufacture and maintain.
In a first aspect of the present invention, an apparatus for dispensing carbonated beverages includes a housing, an ice bin, a carbonator and a cold plate. The housing has an exterior wall. The ice bin is disposed within the housing for storing ice and is surrounded by thermal insulation. The carbonator is disposed within the housing adjacent the ice bin and receives water and CO2 gas to form carbonated water. The thermal insulation is disposed between the carbonator and the ice bin such that the ice bin is thermally isolated from the carbonator. The cold plate is chilled by the ice in the ice bin and includes pre-cooling coils for cooling the water to be supplied to the carbonator and post-cooling coils for cooling the carbonated water flowing from the carbonator.
In another aspect of the present invention, a method for forming carbonated beverages includes the steps of providing a pre-chilling unit and a post-chilling unit chilled by ice, and supplying water through the pre-chilling unit to an uncooled carbonator. The method further includes the steps of supplying pressurized CO2 gas to the carbonator to mix with the chilled water and form carbonated water, and supplying the carbonated water to the post-chill unit to cool the carbonated water.
In still another aspect of the present invention, a carbonated beverage is formed by a method including the steps of providing a pre-chilling unit and a post-chilling unit chilled by ice, and supplying water through the pre-chilling unit to an uncooled carbonator. The method further includes the steps of supplying pressurized CO2 gas to the carbonator to mix with the chilled water and form carbonated water, and supplying the carbonated water to the post-chill unit to cool the carbonated water.
The above, and other aspects, features and advantages of the present invention will be apparent from the following detailed description of the illustrated embodiments thereof which are to be read in connection with the accompanying drawings wherein: